Welded pipe-line joint and method of making the same



Nov. 11, 1924. 1,515,355

H. MITCHELL WELDED PIPE-LINE JOINT AND METHOD OF MAKING THE SAME Filed Jan. 26 1921 INVENTOR.

Patented Nov. 11, 1924.,

- UNITED-STATES *PATENT OFFICE.

HARBOUR MITCHELL, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO .AMmICAN FOUNDRY 6'; CONSTRUCTION COMPANY, OF PITTSBURGH, PENNSYLVANIA, COR- PORATION OF PENNSYLVANIA.

WELDED PIPE-LINE JOINT AND METHOD OF MAKING THE SAME.

Application filed January as, 1921. Serial no. 440,208.

To all whom it may concern:

.Be it known that I, HARBOUR MITCHELL,

residing at Pittsburgh, in the county of' Allegheny and State of Pennsylvania, have invented a new and useful Im rove'ment in Welded Pipe-Line Joints an Methods of Makin the Same, of which the following is a ull, clear, and exact, description, reference being had to the accompanying drawin s, forming part of this specification, in whic 1- Figure 1 is a plan view partly broken away showing one form of oint embodya welded joint between two pieces of ipe by abutting them end to end and ma ing a butt welding connection between them. The ersonal factor of the welder enters very argely into the making of a weld of that character. a

My invention is designed to provide a joint in which there is a positive mechamcal connection between the two pipe sections which is suflicient to prevent their pulling apart or from bursting apart on account of internal pressure, the welding being largely secondary and being used only to prevent leakage, although giving an additional factor of safety against rupture.

In carryin out my invention, I provide the end rtlons of the pipe sections to be joined w1th interfitting tongues and grooves, such tongues and grooves having an interlocking connection when the two sections are membled end to end. A weld is then effected not only between the end edges proper of the pipe sections, but also between the ed es of the projections and the adjacent wa ls of the grooves.

The form and arrangement of the pro ections and grooves may be widely varied, as

may also their number-,the construction being suflicient in any case to give an ample factor of safety.

In the articular. embodiment of my invention w lch I have shown in Figures 1,

.2 and 3, the. numerals 2 and 3 designate two pipe sections to bevjoined,'one of these sections being formed with a plurality of dovetailed projections 4, extending beyond the end edge proper thereof, and the other section having. a plurality of dovetailed grooves 5, each adapted to receive therein one of the projections 4. The width of the projections at their end rtions is preferably greater than the ,wi th of the grooves atthe narrowest portions of the grooves. so as to provide-for an efiicient mechanical interlock. There is, however, preferably a considerable e left between the jaws of the projectlons and the adjacent walls of the grooves, this space being formed by scarfing or beveling the edge rtions of the tongues and groove walls, in order to permit a welding metal to be flowed therein,

as indicated at 6. In the construction illus-' trated in these figures, there are four sets of interlocking grooves and projections.

In assembling the pi sections, it is necessary to leave the pro ections 4 turned upwardly at an angle, as shown in Figure 3. When the sections are abutted, these projections are bent downwardly into their respective ooves. The welding metal is then flowe in to fill the space between the edges of the projections and the walls of the groove andalso between the end edges proper of the pipe sections, the latter being preferably scarfed or beveled somewhat. as indicated at 7, to form a V-shaped surrounding groove to receive this welding metal.

In caseof pipes which are subjected to unusual heavy internal ressures, the joint formed in the manner 9. ve described can be still further strengthened, if desired, by

placing a.- reinforcing band around the joint, as shown in Figure 4, whereone form of such band is illustrated at 8. This band can be spot or otherwise welded to the pipe and when used guards against any'possibility of the joint rupturing by internal bursting pressure. 7

As above indicated, the particular forms of joints which I have herein shown and described are illustrative only, the invenbe welded with intertitting tongues or protions,

jections and grooves adapted to form a.

mechanical interlocking between the said sections for preventing longitudinal separation of the same due to internalpressure,

engaging the tongues or projections of one section with the grooves of the other section by relatively moving the tongues or pro'ections'andgroovw in a direction at an ang e to the longitudinalaxis of the sections, and then :Eorming awelded connection between the abutted and inter-fitted ends of the sections, substantially as described.

2. The method of'forming a welded pipe joint, which consists in providing the pipe sections of members to be welded with inter fitting dovetailed tongues or projections and grooves-abutting the said sections and engaging the tongues or projections and grooveswitheach other by a relative movement between the" tongues or projections and grooves at'an angleto the longitudinal axis of the sections, and then forming a weld between the sections, said weld also extending between the edges of the tongues and the walls ofthe grooves, substantially asdescribed.

3. The method of forming a welded pipe joint, which consists in providing the end portions of the pipe sections to be unitedwith interfittin tongues or projections and grooves adapt to form a mechanical interlocking between the said sections for preventing longitudinal separation of the same due to internal pressure, the tongues extending at an oblique angle to. the longitudinal axis of the sections, abutting the two sections, bending the tongues or projections into engagement with the grooves, and then weldin the adjacent edges of the two sece weld extending between the edges of the tongues or projections and the walls of the grooves, substantially as described.

4. The method of forming a welded pipe joint, which consists in providing the end portions of the pipe sections to be united with interfitting tongues or projections and coves adapted to form a mechanical interocking between the said sections forpreventing longitudinal separation of the same due to internal pressure, the tongues or rojections extending outwardly at an oblique angle'to the longitudinal axis of the sections, abutting the two sections, bending the tongues or projections inwardly into ongagement with the grooves, and then welding the adjacent edges of the two swtions by flowing a welding metal between-the adjacent edge portions of the pipesections and. intothe. grooves around the edges of the tongues or projections, substantially as described.

5. The method of forming a welded pipe joint, which consists in providing the ads jacent end portions of two pipe sections to be welded withinterfitting tongues or projections and grooves adapted to form a mechanical interlocking between the said 4 sections for preventinglongitudinal'separation of the same due to internal pressure, engaging the tongues "01' projections of one section with the grooves of the other section,

forming a welded connection between theabutted and interfitted ends of the sections,

and then securing a reinforcing band to the exterior of the joint, substantially as da scribed.

6. A welded pipe joints-comprising two pipe members having adjacent ends formed with dovetailed interfitting portions united by a filling of welding metal between the end edges of the sections, said'welding-Inemher also extending between and uniting the adjacent edges of the interfitting portions, substantially as described.

7. A welded pipe joint, comprising two pipe members having their abutting ends formed with a plurality of dovetailed.

tongues or projections and grooves, there being an initial space between the edges of the tongue and the walls of the Va, and a filling of welding metal in sai space and forming a weld between said edges and walls, the abutting edge portions proper of said sections being beveled and the grooves.

so formed being filled with welding metal, substantially as described; j

8. A pi e joint,'comprising 'two pipe sections having interfitting tongues or projections and grooves, said sections and the tongues and grooves being welded at their adjacent edges, said welded tongues and grooves forming a mechanical interlocking between the said sections for preventing longitudinal separation of the same due to internal pressure, substantially as described;

9. A welded pipe joint, comprising two pipe sections having abutting end portions, said sections having interfitting vdovetailed tongues and grooves, a welded connection between the ends and between the edges-of the tongues and the adjacent walls of the grooves, and a reinforcing band extending around said joint exteriorly of the pipe sections, substantially as described. I

In testimony whereof, I have hereunto set my hand.

HARBOUR MITCHELL. 

